1. X – ray pick up check
After the circuit board is assembled, X-ray machine can be used to see the BGA underbelly hidden solder joints bridging, open, solder deficiency, solder excess, ball drop, loss of the surface, popcorn, and most often holes.
NeoDen X Ray Machine
X-Ray Tube Source Specification
Type Sealed Micro-Focus X-Ray Tube
voltage Range: 40-90KV
current Range: 10-200 μA
Max Output Power: 8 W
Micro Focus Spot Size: 15μm
Flat Panel Detector Specification
Type TFT Industrial Dynamic FPD
Pixel Matrix: 768×768
Field of View: 65mm×65mm
Resolution: 5.8Lp/mm
Frame:（1×1) 40fps
A/D Conversion Bit: 16bits
Dimensions: L850mm×W1000mm×H1700mm
Input Power: 220V 10A/110V 15A 50-60HZ
Max Sample Size: 280mm×320mm
Control System Industrial: PC WIN7/ WIN10 64bits
Net Weight About: 750KG
2. Scanning ultrasonic microscopy
Completed assembly plates can be inspected for various internal concealment by SAM scanning. Packaging systems can be used to detect various internal cavities and layers. This SAM method can be divided into three scanning imaging methods: A < point-shaped), B < linear) and C < planar), and C-SAM planar scanning is most commonly used.
3. Screwdriver strength measurement method
The torsional moment of the special driver is used to lift and tear the solder joint to observe its strength. This method can find defects such as floating, interface splitting, or welding body cracking, but it is not good for thin plate.
4. Microslice
This method not only requires various facilities for sample preparation, but also requires sophisticated skills and rich interpretation knowledge to get to the bottom of the real problem in a destructive way.
5. Infiltration dyeing method (commonly known as red ink method)
The sample is immersed in a special diluted red dye solution, so the cracks and holes of various solder joints are capillary infiltration, and then it is baked dry. When the test ball foot is forcibly pulled or pry open, you can check whether there is erythema on the section, and see how the integrity of the solder joint? This method, also known as Dye and Pry, can also be formulated with fluorescent dyes to make it easier to see the truth in ultraviolet light.
Post time: Dec-07-2021